I didn't do it properly on purpose, because that wouldn't have been fair towards Go. Ultimately, many things which aren't even common yet today have already existed in the 70s.

I have picked 20 years specifically since it was around 2003-2005 when Java and C# got generics. Obviously, they were also more than 20 years late but I compared it to mainstream languages people are more likely to know about or more likely to compare it with.

I wanted to be fair and compare Go to some other mainstream languages which are big today, not niche ones.